Automatic control for electric irons



C. B. YODhR.

mmmmc mmrm Fm: ELECTRIC moms.

HE'LIFATION HLEU APR. 13. 1920.

1 8,0830 Patented May 17, 1921.

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AUTOMATIC CONTROL FOB ELECTRIC EONS.

Specification of Letters Patent.

Patented May 17, 1921.

Application filed April 19, 19:20. Seriai No. 374,988.

T 0 all whom it may concern: I

Be it known that I, CHARLES B. Yonnn, a citizen of the United States,residing at Webster Groves, in the county of Saint Louis and State ofMissouri, have invented a new and useful Automatic Control for ElectricIrons, of which the following is a specification.

My invention relates to improvements in automatic control for electricirons, and my object is to provide an electric iron, haxdng a switch forcontrol of electric energy, with means, of simple and inexpensiveconstruction for automatically operating the switch, comprising anelement susceptible to expansion by heat, and arranged to cut 05 theswitch upon reaching a predetermined heat maximum.

My improvements consist in the novel construction, arrangement andcombination of the elements as hereinafter fully, clearly and conciselyset forth, definitely pointed out in my claims and illustrated by theaccompanying drawing, in which- Figure 1 shows in plan an ironconstructed in accordance with my invention.

Fig. 2 is a longitudinal sectional elevation of the iron, and

Fig. 3 is afragmental, sectional plan view, taken approximately on theline designated 3-3 of the Fig. 2.

Referring by numerals to the drawings% I designates the iron, proper,which, as is common, is constructed with a smooth-finished surface 5,and provided with a head 6, secured to the iron proper 4 by screws 7.

Between the iron proper and its head 6 there is placed a heating element8. Surmounting the head is a finish hood 9, which is secured to the headby a screw 10 and secured to the hood is a bow 11 to which the operatinghandle 12 is secured.

l3 designates an electric switch comprising a push button 14: and a leafcontact or circuit making and breaking device 15, binding screws 16 forservice wires and conductors (not shown) leading to the heat-. ingelement 8, through the insulating tubes 17 Formed longitudinally throughthe iron proper there is a bore 18 having a thread 19 within its lengtharranged to receive a rod 20 of greater coexpansive efliciency than ironproper, such for example as an aluminium rod. This rod is provided withan enlarged and externally threaded head 21 having rotating means suchas the driver slot 22.

Formed vertically through the iron near its heel there is a cavity 23,intersecting the bore 18 and arranged to receive a bearing 24 in whichthere is pivotaily mounted a bell crank lever whose short arm isarranged to engage the end of therod 20 and whose upper end extendsupwardly through a hole 26.:tormed in the hood 9.

A spacer, or distance block is secured to the handle and its .bow andextended transversely therethrough is a pin 27 on which there is carrieda cam 28 which operates the circuit maker and breaker 15. This cam isprovided with a notch 29 into which the upper end of the long arm of.the bell-crank 25 is fitted, so that upon an expansion of the rod 20,upon a predetermined temperature, the bell-crank efiects a rotation ofthe cam 28 to an extent to free or break the circuit maker and breaker15, and hold it in broken circuit until restored by a manipulation ofthe push button, which latter can only be effected after the iron hasbeen sutficiently cooled.

The cam is actuated in one direction by a coil spring 30 (Fig. 3) and solong as the bell-crank is not moved by the expansion rod 20 the camserves to hold the circuit maker and breaker in closed position.

Assuming the iron to be properly connected with a source of elect icalenergy, the iron cool and the circuit broken by the switch, the operatordepresses the push button 14 to establish circuit with the heatingelement 8. In this condition the spring 30 is holding the cam 28 in aposition to maintain the circuit. Assuming now that the iron reaches atemperature above what is necessary or desired, it will be apparent thatthere will be linear expansion or" the rod 20, which being held againstlongitudinal movement by its threaded head 21 its rear end will beextended to engage andopcrate the bell-crank 25. Upon a rocking of thecrank .25 the cam 28 is rotated and its face freed or moved to'allow theleaf cir cuit maker to break, thus cutting 0d the supply of energy tothe heating element.

I claim:

1. In combination with an electric iron having a circuit controllingswitch, a switch operating means comprising a cam for engagement withthe circuit making and breaking device, a bell crank for engagement withthe cam and a rod, susceptible of for holding one end of the rm againstllnear expansion by heart, acfimg; upon said 'mm'ement, a bell-crankacted upon by sax} bell-crank. rod, a cam movable by said ball crank, a10 2. An iron of the class described having switch, operable by said;cam, and a heating 5 21- bore formed there-through, a rod, of alemeno incircuifi with the switch."

greater coexpansim efficiency than sa-ic i iron, extended through saidbore, means CHARLES B. YODER.

